The owner of Captain Chicken at Ascot Park, Terry Stephens, said his order of Lilydale chickens failed to arrive on Christmas Eve.

He was told of production problems, including chickens dying in the weekend's extreme heat.

Mr Stephens said he had hundreds of orders to fill and remained hopeful of a late delivery.

"You have a feeling that people have entrusted you with their Christmas lunch and you don't want to let them down, so we're very mindful of the fact that it could upset people's Christmas Day plans," he said.

Retailers have had a busy trading day across South Australia.

Many shoppers found it hard to move around the Central Market in the city, as they tried to stock up on food for the next day.

Delivery vans kept pulling up in Gouger Street with more supplies, but butcher Alex Savvas said some of the Christmas essentials were sold out very quickly.

"[I was] very surprised with the turnout of people. Sold out of on-the-bone Christmas leg hams by about nine o'clock this morning," he said.